Here’s an excerpt from their “About” page:
Smarthistory.org is a free multimedia web-book designed as a dynamic enhancement (or even substitute) for the traditional art history textbook. Dr. Beth Harris and Dr. Steven Zucker began smARThistory in 2005 by creating a blog featuring free audio guides in the form of podcasts for use in The Museum of Modern Art and the Metropolitan Museum of Art. Soon after, we embedded the audio files in our online survey courses. The response from our students was so positive that we decided to create a multimedia survey of art history web-book. We created audios and videos about works of art found in standard art history survey texts, organized the files stylistically and chronologically, and added text and still images.Of course it’s not “comprehensive”, but it’s pretty vast nevertheless. It’s all western art and, as far as I can see, mostly from New York collections (which is hardly surprising, considering its origins). But I’m intrigued by the use of video to concentrate on individual works of art. Eg: have a look at the page on Diane Arbus’ Boy with a Toy Hand Grenade - For the first 2 minutes, all you see is the artwork. Then, the photographer’s contact sheet. Then the photograph again but, as the two discuss it, you see their mouse pointer moving around the image. Very simple, basic technology (which produces a slightly annoying trail of tiny, vertical lines) but it does the job.
I also like the way you can explore by time, style, artist and theme.
Also worthy of note is how they have allowed public participation by integrating photos from their own Flickr group.